Patches of soft, matted grass develop in the lawn. Sometimes the grass looks dead, with long, straggly stems. In the spring, it greens up more slowly than the surrounding grass. Bentgrass needs to be cut short (1/4 to 1/2 inch tall), as it is on golf course putting greens, to be attractive. The invasive nature of bentgrass makes it a weed in bluegrass and ryegrass lawns, which are cut 1 1/2 to 2 inches tall. Bentgrass will crowd out other grasses.
Omit a regular mowing before treating to allow for enough leaf tissue to absorb the chemical. One week after spraying, mow the bentgrass close and reseed the area.